Guiding the humoral response against HIV-1 toward a MPER adjacent region by immunization with a VLP-formulated antibody-selected envelope variant

PLoS One. 2018 Dec 19;13(12):e0208345. doi: 10.1371/journal.pone.0208345. eCollection 2018.

Abstract

Preventive HIV-1 vaccine strategies rely on the elicitation of broadly neutralizing antibody (bNAb) responses, but their induction in vivo by vaccination remains challenging. Considering that the ability of an epitope to elicit effective humoral immunity depends on its exposure on the virion, we have used a reverse genetics approach to select variants from an HIV-1 AC10_29 randomly mutated envelope library that showed increased affinity for a selected bNAb (4E10 bNAb targeting the HIV-1 MPER region). Isolated envelope sequences were analyzed by deep-sequencing showing a small number of dominant changes, including the loss of four potential N-linked glycosylation sites and disruption of the V1/V2 loop. Accordingly, the dominant variant (LR1-C1), showed not only increased affinity for MPER bNAbs 4E10 and 2F5, but also higher affinity for an additional antibody targeting the V3 loop (447-52D) that could be a consequence of an open conformation tier 1-like Env. Furthermore, the amino acids specific for the selected variant are associated with an increased sensitivity for 4E10 and 2F5 antibodies. In vivo studies showed that sera from mice immunized with LR1-C1 viruses possessed an improved neutralizing activity compared to the wild-type AC10_29 env. While Virus Like Particles (VLPs) carrying this envelope were unable to induce detectable neutralizing activity in immunized rabbits, one animal showed antibody response to the 4E10-proximal region. Our data establish a novel approach that has the potential to yield HIV envelope immunogen sequences that direct antibody responses to specific envelope regions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neutralizing / immunology
  • Antibody Formation / immunology
  • Blotting, Western
  • Cryoelectron Microscopy
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • HEK293 Cells
  • HIV Antibodies / immunology
  • HIV-1 / immunology*
  • Humans
  • Immunity, Humoral / immunology*
  • Immunization
  • Mice
  • Mice, Inbred BALB C
  • Neutralization Tests
  • Rabbits
  • Vaccines, Virus-Like Particle / immunology

Substances

  • Antibodies, Neutralizing
  • HIV Antibodies
  • Vaccines, Virus-Like Particle

Grants and funding

Funded by COMISIÓN NACIONAL DE INVESTIGACIÓN CIENTÍFICA Y TECNOLÓGICA (CHILE): CAROLINA BELTRAN-PAVEZ, PORTUGUESE FOUNDATION FOR SCIENCE AND TECHNOLOGY (PORTUGAL): CAROLINA B FERREIRA, SPANISH MINISTRY OF ECONOMY, INDUSTRY AND COMPETITIVENESS AND EUROPEAN REGIONAL DEVELOPMENT FUND (CTQ2015-63919-R): ISABEL HARO. HIVACAT PROGRAM: CHRISTIAN BRANDER, FELIPE GARCIA, JOSE M GATELL, ELOISA YUSTE AND VICTOR SANCHEZ-MERINO, Horizon 2020: H2020-SCI-2016-2017 (731626), FELIPE GARCIA; H2020-SC1-2016-RTD (SAF2015-66193-R), FELIPE GARCIA; EAVI2020 (GA681137), CHRISTIAN BRANDER; EHVA (681032), ELOISA YUSTE, VICTOR SANCHEZ-MERINO AND FELIPE GARCIA. RED ESPAÑOLA DE INVESTIGACIÓN EN SIDA RD16/0025/0014 and RD12/0017/0001): FELIPE GARCIA, ELOISA YUSTE AND VICTOR SANCHEZ-MERINO. MINISTERIO DE ECONOMÍA Y COMPETITIVIDAD. SUBPROGRAMA INNPACTO (IP-2012-0325-010000): ELOISA YUSTE, MINISTERIO DE CIENCIA E INNOVACIÓN (RYC-2007-00788): ELOISA YUSTE, FIPSE (36780/80): ELOISA YUSTE.